I've cut out the piece of plastic that will serve as the second floor of the new habitat. Also measured and cut the dowels that will support it and found all of the nuts/bolts I'll need for mounting the dowels, the ballast pods and the skylight.
This thing really is big. I'm not sure how apparent it is from the pic below (I included one of the running saucers for scale) but even one floor of it is about 30% larger than Hambase Alpha. And there'll be two such floors, with enough vertical room that both could have a running wheel if necessary. Or two each?
Tomorrow I'll run out to Home Depot and look for a piece of lexan suitably sized for the 'skylight'. Probably the same precut piece I also used as the front and side windows for my diving helmet as they happen to be exactly the right size for this as well.
Adding in a skylight is only necessary to begin with because the enclosure didn't turn out to have a transparent lid as advertised. It bothers me that I'll have to compromise the integrity of the enclosure so much by cutting out a frame for the lexan window, mounting it with bolts and sealing it with silicone/cyanoacrylate, but as the lid is very rigid and doesn't flex much I expect to be able to make it very watertight. The opaque rim of the lid will also give me someplace discreet to mount down-facing LED light strips later on.
As an aside, I tried to sink this sumbitch in the tub using all six of the 5lb lead block weights I have now but it wouldn't sink. Which means the dual Otterbox 3000 ballast pods I used for Hambase Alpha will not cut it here. Even three of them won't be sufficient. Luckily the same company makes a container with the same footprint, but twice as 'deep', the Otterbox 3500. This means I can fit four block weights (20lbs) into each ballast pod.
This should allow me to mount either two (for a total of 40lbs) or three (for a total of 60lbs) as necessary. At this point I strongly suspect it'll take three of 'em. This will put the ground floor up a little bit higher than Hambase Alpha's, but when I get around to connecting them with the modular gate/tube system, the tubing is flexible so a slight elevation difference shouldn't be a big deal.
Here's the type of weight I need > (Link) There it appears to be sold in lots of 8. There are two such lots remaining. Buying both would give me enough weights for Hambase Delta, plus four extra I could use for the removable food module and the removable waste module. If a wealthy, generous, mentally unbalanced person is reading this and would like to greatly accelerate work on this project for his or her own perverse satisfaction, I'll need about $220 to buy the weights I need plus another $60 for 3x Otterbox 3500.